For the measurement of the
global radiation and/or the
Albedo on different surfaces.
The upper Pyranometer measures
the infalling global radiation,
and the lower instrument
the radiation reflected by the
surface.

Instrument for the measurement
of the net radiation, that means
the instrument forms the difference
between the global radiation
from above (solar radiation
and long-wave atmospheric
counter radiation) and the
global radiation from below
(short-wave and long-wave
reflection radiation of the earth).